System for automated detection in beverage dispensing machines

ABSTRACT

Means are provided for the support of the automated process of supplying beverages. More particularly, the detection of the presence and the contents of exchangeable supply packs in beverage dispensing machines is automated. A pack-in-place detection is provided by emitting light and measuring the presence of the emitted light on one light detector, the system determines the absence or the correct/incorrect placement of the supply pack. A product availability detection is provided by detecting the intensity of light coming through a transparent element in the supply pack by another light detector, the system identifies the degree of product presence in the supply pack.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a divisional of U.S. application Ser. No. 14/581,149, filed Dec. 23, 2014, which is a continuation of International Patent Application No. PCT/NL2013/050477, filed on Jul. 1, 2013, which claims the benefit of priority to Netherlands Application No. NL2009092, filed on Jun. 29, 2012, all of which are hereby incorporated herein by reference in their entireties.

BACKGROUND

The invention relates to a system comprising a beverage dispensing machine and an exchangeable supply pack comprising a doser which system comprises means for automated detection of the presence of the exchangeable supply pack and of the product in the exchangeable supply pack.

Service providers of beverages distribute their beverages mostly via automated dispensers in offices, public venues and other locations. Such beverage dispensing machines can include coffee machines for preparing hot beverages or post mix juice dispensing or vending machines for such products. Enhancing the ease of use when operating these beverage dispensing machines is crucial, not only for the consumer but also for the supplier. In the supply process, service providers are challenged to minimize human interference and maximize the degree of automation, for reasons of costs, efficiency and failure reduction. The present invention provides a robust, easy-to-use, failsafe and cost effective system for the support of the automated process of supplying beverages.

Pack and supply recognition in a beverage machine is disclosed in several documents such as DE 102008055949 and US 2005/022674. While each of the prior art supply detection means are reasonably effective, these all require a substantial effort as regards to sensors that need to be sensitive and accurate and the electronic systems involved. A drawback of such sensors and electronic systems is that these are relatively costly and require great attention to detail, not only in their being incorporated in appliances, but also regarding the product supply packs with which they have to be compatible.

SUMMARY OF THE INVENTION

Accordingly it is an object of the present invention to propose an improved system for automatically performing supply detection, such as detection of pack positioning (pack-in-place) and product availability. In a more general sense it is an object of the invention to overcome or ameliorate at least one of the disadvantages of the prior art. It is also an object of the present invention to provide alternative systems which are less cumbersome in assembly and operation and which moreover can be made relatively inexpensively.

To this end the invention provides a system as defined in the appended claims. Such a supply detection means has the benefit of being relatively simple and reliable. The invention further provides for a reliable and possibly also failsafe distinction between individual signals generated by the first and second detectors, when a transmitter is used.

Detection and Recognition.

The invention automates the detection of the presence and the contents of exchangeable supply packs in beverage dispensing machines. The invention may use light detection for the automated detection of pack positioning and product availability. An advantage of this system is that there is no physical contact between the first and second interface.

System.

The invention provides a system comprising a beverage dispensing machine and exchangeable supply packs comprising a doser which packs are adapted to contain a product to be supplied in the operation of the system.

Means.

The invention uses radiation such as light for the automated detection and recognition. More particularly, the invention may include several light sources and detectors in combination with transparent and opaque elements being part of the doser.

Pack-in-Place Detection.

By emitting light and measuring the presence of the emitted light on a light detector, the system determines the absence or the correct/incorrect placement of the supply pack. More particularly, when the light does come through unhindered, the supply pack is absent or not properly placed.

Product Availability Detection.

By detecting the intensity of light coming through transparent elements in the doser, the system identifies the degree of product presence in the supply pack.

Components for the Determination of Pack and Product Presence.

The presented means for supply detection uses two light detectors. A transparent element of the doser is positioned between a transmitter and the first detector. An opaque element of the doser is positioned between a transmitter and the second detector. This measure provides for failsafe distinction between individual signals generated by the first and second detectors. Examples of transmitters include infrared (IR) light transmitters or light emitting diodes (LED).

The invention can be arranged to verify whether a signal generated by the first detector is below or above a predefined threshold. It can also be arranged that when the first detector detects radiation above the predefined threshold in combination with the second detector generating substantially no signal, a period of time lapsed after activation is considered to determine whether a positioned pack is empty or full, but still unopened.

This way a complete lack of signal or unexpected levels from at least one of the first and second detectors could be interpreted as a failure condition.

Splitting the detection into two sensors enables a cost effective, reliable and simple detection method as opposed to a single sensor that needs to be very accurate and is therefore expensive.

It has also been found that the end of product availability can be physically indicated by the presence of air in the liquid product as it is dispensed. The detection system uses the change in refractive index between a liquid and air to amplify the presence of air in the fluid as is passes into the pump. Therefore, it is advantageous that the transparent element of the doser is an optical element whereby it is only required that such an optical element can be utilized to alter a direction of light falling onto this optical element. The optical element can be in any shape or form that makes use of the difference in refractive index of fluid and air. The presence of a liquid in the transparent element of the doser causes the light from the transmitter to continue into the liquid and to be detected by the first detector. When air is present in the transparent element the direction of the light is altered. The deflected light is preferably detected by a third detector. Preferably, the first detector is then substantially aligned with the transmitter on a common axis and the third detector is then directed perpendicular to the common axis. More preferably, the optical element is a prism. Most preferably, the prism includes a plurality of prism facets (71). The third detector may be a reflection sensor

The system uses exchangeable supply packs comprising fluid substances that are used in the preparation of a beverage for a user. The fluid substance may include but is not limited to coffee extracts, tea extracts, chocolate beverages, milk, flavours, juices, and/or concentrates thereof.

Examples of exchangeable supply packs are bag-in-box packs or rigid containers as disclosed in WO 2011/049446. An example of the doser is as disclosed in WO 2011/037464. The whole housing of the doser may be used as the second interface. Alternatively, only part of the doser includes the second interface.

In a further embodiment, the exchangeable supply pack may additionally be provided with a removable or pierceable seal, which separates the doser from the main body of the exchangeable supply pack that forms the actual fluid container. This seal covers the outlet opening of the actual fluid container, and is automatically broached by mechanical piercing or pushing out of the removable seal upon full engagement of the doser with the machine interface. This auto-broaching system is disclosed in an internet publication published on Apr. 12, 2011, http://pdfcast.org/pdf/auto-broaching.

In another embodiment, the doser and the exchangeable supply pack may be two separate elements whereby the doser may be connectable to the exchangeable supply pack.

The system of the present invention is described by the use of a supply detection arrangement for one exchangeable supply pack comprising a doser. However, a beverage dispensing machine may comprise more than one exchangeable supply pack. Accordingly, the system of the present invention may comprise one or more means for automatically detection depending on the number of exchangeable supply packs in the system.

The use of the expressions “substantially transparent” and “substantially opaque” should not be construed to limit the present invention. These expressions as used herein, are understood to refer to the respective possibilities of viewing through, allowing light to be transmitted there through, and effectively blocking all light. In its broadest sense these terms mean that the first element is able to let through more radiation than the second element. Another term for transparent can be translucent. Another term for opaque can be reflective.

BRIEF DESCRIPTION OF THE DRAWINGS

Detailed aspects and further advantages of the invention will be explained in reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a supply detection arrangement according to the invention with a fully and correctly inserted exchangeable supply pack comprising a doser;

FIG. 2 is a schematic view of a machine interface of the detection arrangement with an exchangeable supply pack comprising a doser not yet inserted;

FIG. 3 is a schematic view of the machine interface with an exchangeable supply pack comprising a doser that has not fully been inserted;

FIG. 4 is a schematic view of the machine interface with a fully and correctly inserted exchangeable supply pack comprising a doser;

FIG. 5 is a schematic view of an inserted exchangeable supply pack comprising a doser that is empty, or that has been emptied;

FIG. 6 is a schematic view of a further embodiment that has a removable seal in the exchangeable supply pack, which has not been opened;

FIG. 7 shows schematic detector readings over time for pack-in-place detection (PIP) and product availability detection (PAD)

FIG. 8 shows a side view of an alternative embodiment of the present invention;

FIG. 9 is the perspective view of the embodiment of FIG. 8;

FIG. 10 is a supply detection arrangement according to the invention;

FIG. 11 is an exploded view showing the primary components of an alternative form of a doser for a system according to the invention;

FIG. 12 shows the assembled doser of FIG. 11 with an optical detection arrangement that is part of a beverage dispensing appliance;

FIG. 13A is a schematic representation of a prism operation with air, FIG. 13B is a schematic representation of a prism operation with water, and FIG. 13C is a detailed view of a stepped prism design;

FIG. 14 is a general arrangement for the optical system of FIG. 12, as seen from above;

FIG. 15 is a detail cross section view, on an enlarged scale, of a flow diverter;

FIG. 16A and FIG. 16B show views of the doser without supply pack as inserted in its home position with respect to a part of a beverage dispensing appliance that carries the optical sensor arrangement;

FIG. 17 is a partial perspective detail view showing detection tab for pack approaching detection;

FIG. 18 is a partial cross section of a gear pinion about to engage a drive shaft of the beverage appliance; and

FIG. 19A and FIG. 19B schematically show the doser lowering into position at larger (FIG. 19A) and smaller (FIG. 19B) distances of approaching.

DETAILED DESCRIPTION

A preferred embodiment of the present invention uses double detection of a light beam, such as an Infra Red (IR) beam, radiated by a single transmitter, for detecting product positioning and product availability. It is expressively implied that transmitters and sensors in other frequency ranges of the spectrum can also be used.

As shown in FIG. 1 a suitable means of detection can be an IR detection arrangement 1 with one single IR-transmitter 3 and first and second detectors 5, 7 instead of only one, as in conventional systems. The first detector 5 together with the IR-transmitter 3 for detecting product availability is proven technology and has been used before in detection systems. A second detector 7 is used to detect whether an exchangeable supply pack 9 comprising a doser 11 is in place. The detection arrangement 1 is part of a system that includes a beverage dispensing machine (not shown, but conventional) and at least one exchangeable supply pack comprising the doser 11. Such machines comprise at least one first or machine interface 13 for receiving at least one exchangeable supply pack 9 at at least one position. The doser 11 comprises a fluid connector and a dosing mechanism, such as a pump (not shown), and acts as a second or pack interface.

With the arrangement according to FIG. 1 detections are possible as discussed in reference to FIGS. 2 to 6. In FIG. 2 and subsequent FIGS. 3 to 6 arrows depicted at the transmitter 3 and the first and second detectors 5, 7 will schematically indicate activity of the transmitter or the respective detector.

In FIG. 2 a situation is depicted that a full exchangeable supply pack 9 comprising a doser 11 is not yet received between the transmitter 3 and the first and second detectors 5 and 7. Each of the first and second detectors is now exposed to the unobstructed radiation of the transmitter 3. This is characteristic for a situation that no pack is present. The doser 11 acts as a second or pack interface for cooperating with the first, or machine interface 13.

In FIG. 3 a full exchangeable supply pack 9 is shown whereby the doser 11 of the supply pack 9 is partly inserted between the transmitter 3 and the first detector 5. The doser 11 has an upper part 11A that is substantially transparent. The doser 11 further has a lower part 11B. The lower part 11B of the doser 11 is substantially opaque. When the first detector 5, as shown in FIG. 3, does not detect any radiation from the transmitter and when at the same time the second detector 7 detects the unobstructed radiation from the transmitter 3, then it can be determined that the pack 9 is not correctly inserted.

In FIG. 4 it is shown that the full pack 9 is properly inserted, with the upper part 11A facing the first detector 5 and the lower part 11B facing the second detector 7. In this case the pack 9 is full and thus filled with a liquid product. In this case the upper part 11A is filled with the liquid contents of the pack 9. Light emitted from the transmitter 3 is detected by the first detector 5 through the substantially transparent upper part 11A and the translucency of the liquid. This results in a signal generated by the first detector that is below a threshold typical for liquid detection (product availability). The second detector 7 receives no radiation from the transmitter 3, due to the opacity of the lower part 11B of the doser 11. This can be interpreted as a properly inserted full pack.

In FIG. 5 the same situation as in FIG. 4 is shown, except that here the pack 9 has reached an empty state. Here the partly translucent liquid product has sank below the level of the first detector 5, which now receives radiation from the transmitter 3 that is only obstructed by the transparent outer wall of the upper part 11A. This results in a different signal being generated by the first detector 5 that is above a predefined threshold, typical for an empty upper part 11A.

In a variation shown in FIG. 6, the pack 9 is additionally provided with a removable or pierceable seal 15, which separates the upper part 11A from the main body of the pack 9 that forms the actual fluid container. This seal 15 covers the outlet opening of the actual fluid container, and is automatically broached by mechanical piercing or pushing out of the removable seal 15 upon full engagement of the doser 11 with the machine interface 13. As shown in FIG. 6, the removal of the seal 15 has not been properly performed and no liquid has consequently entered the upper part 11A. This results in a combined reading of the first and second detectors 5 and 7 that differs from that in the situation of FIG. 4 and hence an unsuccessful broaching of the pack 9 can be detected. Basically the combined reading of the first and second detectors 5 and 7 is the same as in the situation of an emptied pack (FIG. 5), but the non-broached diagnosis can be related to the directly preceding pack insertion action having resulted in various changes of the detector readings.

The available detector readings are assembled in Table 1.

TABLE 1 First detector (5) Second detector (7) Pack (9) Below threshold Below threshold Present and full Below threshold Above threshold Misplaced or in process of placement/removal Above threshold Below threshold Empty or not broached Above threshold Above threshold No pack present

As shown in Table 1, double-conditions exist. To distinguish between these conditions it is also possible to make use of interaction with a door or hatch of a pack compartment of the machine. It is thus possible with such a door being closed or with the machine in start-up when this detector reading occurs to give the ‘not broached’ condition a higher priority. It is also possible to activate the machine to retry broaching of the pack seal, even when it was already broached at an earlier stage. When after, for example, two seconds no fluid enters the dosing room of the upper part 11A, a valid conclusion is generated that the pack 9 is empty.

Alternatively the non-broached and empty-pack diagnosis can also be related to a period of time that has lapsed after the appliance was last switched on.

By plotting the signals of the first and second detectors 5 and 7 over time it can be determined whether a pack is being placed or removed. This is shown in FIG. 7 wherein schematic detector readings over time are shown for pack-in-place detection (PIP) and product-availability-detection (PAD) and the resulting diagnosis.

An additional requirement is to perform the above explained product availability and/or pack-in-place detection for misplaced packs in a failsafe manner. In order to make the detection fail safe the valid detection range lies between 0% and 100%, which are typical failure modes of these type of detectors. A suitable testing routine can be provided by disconnection of the sensors or transmitter. To create a failsafe path in this, it is further proposed that the doser does not block light 100% for pack presence detection but by way of example only 70%. When 100% blocking is detected then likely something else has occurred, like a detector or transmitter having become defective. Examples are given in Table 2, which also includes the typical failure modes of the detectors.

TABLE 2 Trans- first second mitter (3) detector (5) detector (7) Pack (9) OK <80%   30% Present and full OK   30% >90% Misplaced OK >80%   30% Empty or not broached OK >90% >90% No pack placed OK Defect 0% >90% Misplaced OK Defect 100% >90% No pack placed OK — Defect 0% Second detector (7) Abnormal low −> error OK — Defect 100% Misplaced Defect  0%  0% Second detector pack Abnormal low −> error

It is apparent that when in fail mode a transmitter is not transmitting any light anymore or a sensor is detecting no light anymore this is detectable in system when the light damping of dosing pack-presence part is by way of example 60 to 70% rather than 100%.

FIGS. 8 and 9 show an alternative embodiment in side and in perspective view. This embodiment is a doser according to the principles as disclosed in WO 2011/037464. The two required elements are positioned besides the in and outlet of the doser that comprises a fluid connector and a dosing mechanism, such as a pump (not shown). The doser 11 has an upper part 11A that is substantially transparent, and that is filled with the liquid contents of the pack 9 (not shown). The doser 11 further has a lower part 11B. The lower part 11B of the doser 11 is substantially opaque. FIG. 9 shows the spout 17 for connecting the doser 11 to the exchangeable supply pack. FIG. 10 shows a supply detection arrangement 1 according to the invention wherein the doser according to FIGS. 8 and 9 fits. It clearly shows the transmitter 3 and the first and second detectors 5, 7.

An alternative doser 31 is shown in FIG. 11. A first substantially transparent element 49 can be seen protruding from the right hand side of the doser 31. A stepped/serrated feature 51 provides the optical element of the system, as will be explained below. The doser further includes a bottom housing 39, a pump housing 41, and a top cap 43. The bottom housing 39 is the main housing of the doser 31A pump accommodated in the pump housing 41 is a gear pump with a pair of mutually engaging gear pinions 45, 47. One of the gear pinions 45, 47 of the pair is arranged for coupling to a drive shaft of a beverage dispensing machine.

The pump housing 41 provides the body of the gear pump and both an inlet and outlet orifices for the pump. In the specific embodiment, as described here an extension 55 in the fluid flow path 53 can be seen on the right hand side of the pump housing 41. This extension 55 functions as a flow diverter. This flow diverter 55 ensures that product drawn into the pump passes through the first substantially transparent element, in the present FIG. sample chamber 49, and hence through the field of view of an optical system to be described below. It should be understood however that the flow diverter is an optional element not essential to the operation of the optical system.

The top cap 43 mounts to the bottom housing 39. The top cap 43 is used for attachment of the doser 31 to an exchangeable supply pack (not shown, but conventional).

FIG. 12 shows the doser 31 of FIG. 11 in assembled condition and in position with respect to a detection arrangement. The end of product availability (liquid presence), in the alternative embodiment of doser 31, is physically indicated by the presence of air in the liquid product as it is dispensed. The detection system uses the change in refractive index between a liquid and air to amplify the presence of air in the fluid as is passes into the pump. An example of this optical effect is schematically shown in FIGS. 13A, 13B, and 13C.

Light from an external light source 57 is directed towards a prism 59 that forms a part of the sample chamber 49. Here the prism 59 acts as an optical element, which can be an element in any shape or form that makes use of difference in refractive index of fluids and air. It is only required that such an optical element can be utilized to alter a direction of light falling onto this optical element. The light from the light source 57 passes through an external wall 61, but is reflected from an internal inside wall 63 when air is in the sample chamber 49 (see FIG. 13A). The reflected light then exits the prism 59 where it is detected by a third detector, e.g. a reflection sensor 65.

The presence of a liquid in the sample chamber 49 (see FIG. 13B) changes the refractive index at the internal inside wall 63 causing the light to continue into the liquid instead of being reflected. Light emerging from a far chamber wall 67 is detected by a first detector, e.g. transmission sensor 69.

To reduce cost and improve manufacturability the solid prism 59 of the schematic FIGS. 13A and 13B are replaced by a series of smaller plurality of prism facets 71 shown in FIG. 13C. In the embodiment described the prism facets 71 form the stepped serrated feature 51 at an exterior of the inside wall 63 of the sample chamber 49. In other conceivable examples the whole housing of the doser might be used as the sample chamber and the prism facets could be incorporated into the housing side wall.

The prism facets 71 act to amplify the presence of air in the sample chamber by switching light towards the reflection sensor 65 when air is present on the inside wall 63. A further method of improving detection is the monitoring of the various sensors during a pumping cycle. Usually such internal reflection sensors 65 could be used as static device in that the presence of air is only tested before or after the dispense cycle.

The viscous and non-homogeneous nature of some liquids, especially liquid coffees, makes such an approach problematic. By monitoring the reflection and transmission sensors 65, 69 while the pump is operating it is possible to detect air bubbles entrained in the liquid. By careful design of the doser 31 it is possible to ensure that the entrained bubbles pass through the sensors' field of view. A further design consideration is to ensure that the bubbles are forced into contact with the internal wall 63 of each of the prism facets 71. This both improves detection and acts to clean the internal surfaces of product build up.

In the schematic example described above, in reference to FIGS. 13A and 13B, a solid triangular prism 59 is used as the optical element in the system. The angle of the internal wall 63 is chosen as a function of the differing refractive index of air and the liquid to be measured. The angle is determined by optical analysis. Under ideal conditions with air in the sample chamber 49, all light is reflected to the reflection sensor 65 placed at 90 degrees to the incident light. Testing with various moulding techniques has shown that the optical performance is relatively unaffected by the slumping of surface features. The detection technique could therefore also use a solid prism. FIG. 13C shows the stepped prism design, using the plurality facets 71. In practice it is preferred that a low volume of plastic be used. The solid prism 59 has been implemented using a series of smaller triangular facets 71. These facets 71 form a step feature 51 as shown in FIG. 13C. Again the angle of the internal face or wall 63 is optimized through analysis. The size of the steps is a function of the light transmitting source 57 output angle and the reflection sensor 65 input angle. The facet steps 71 are typically at 90 degrees (but can be optimized if required). The surface finish should be flat and smooth to prevent surface scattering/lensing. Analysis has shown that a certain draft on either or both surfaces does not have a significant impact on its performance. The design is reasonably tolerant of variations due to manufacturing tolerances.

In the present embodiment the flow diverter 55 is optionally employed to ensure correct operation in that the product must pass in front of the detection system as it is pumped. The flow diverter 55 has been added in the flow path 53 of the pump to ensure that product is drawn through the sample chamber area 49. The flow diverter 55 does not intervene with the existing pump inlet opening size. A side view of the flow diverter is shown in FIG. 15. The flow diverter 55 provides several advantages, in that:

-   -   it directs product flow, and in particular air bubbles, in front         of the reflection sensor 65;     -   it is sized in one axis to ensure that air bubbles will touch         the inner wall 63 of the prism facets 71;     -   it does not interfere with the sensor field of view because it         allows light to be conducted directly through clear plastic of         the flow diverter 55 through to the transmission sensor 69 thus         reducing the signal to noise ration of the system; and/or     -   it is designed in shape and positioning to achieve the above and         to provide a ‘washing’ action against the inside of the prism         facet, by guiding the fluid in contact therewith.

The doser 31, as stated above, forms part of an exchangeable supply pack embodied as a bag-in-box consumable. The pack is placed into the coffee machine/dispenser where the optical detection system is located. The doser 31 is shown in FIG. 16A engaged with an interface part 73 of a dispenser appliance. Thereby the doser 31 acts as a pack interface. Locating handles and other mechanisms are not shown to simplify FIG. 16A. The optical components are located in the dispenser interface part 73 around a cavity 74 housing the sample chamber 49 with its prism facets 71. Looking at the right hand FIG. 16B the light source 57 is located to the right of the prism facets 71, as will be understood in conjunction with FIGS. 12 and 14. The reflection sensor 65 is located directly above the prism facets 71 (as illustrated in FIG. 16B), while the transmission sensor 69 is located to the left of the prism facets 71.

A further function of the optical system is to confirm that the exchangeable supply pack has been properly loaded into the dispenser appliance. In this regard a separate Pack-in-Place (PIP) sensor 75 is located below the transmission sensor 69 at the left of the prism facets 71, as shown in FIG. 12.

The dispenser appliance thus include, the detection system as shown in FIG. 12 and contains a number of advantageous features as will be described below. The transmission light source 57 for the detection system may be a light emitting diode (LED). To provide maximum penetration of the product an infrared LED (wavelength ˜880 nm) is preferred. The system will however also work at other wavelengths and has also been successfully tested at 650 nm. Generally a light emitting diode (LED) with a wavelength in a range of 500 nm to 950 nm, preferably within a range of 650 nm to 880 nm is suitable.

The preferred wavelength is a function of the product's spectral absorbance characteristics. For the more commonly used transmission only type systems (shining through product) the wavelength will be tuned so that the maximum attenuation is achieved when the product is present. As noted earlier the build up of product on the side walls can make this approach problematic.

For the proposed detection system the wavelength is chosen so that maximum transmission can be achieved. This allows light entering the sample chamber 49 to penetrate any film present that might be obscuring an air void behind. A further advantage of an infrared light source is that it is not readily detected by a consumer during pack replacement.

A second aspect of the transmission LED is its output beam angle. Illuminating the side wall of the sample chamber 49 with a wide angle light source will result in light propagating into and around the clear plastic side walls of the dosing assembly 31, This light can exit the side walls at various parts of the doser in an uncontrolled way and may make its way into the sensors in a rather uncontrolled manner. The result is that the sensors see some form of signal when in fact none should be present (reduced signal to noise ratio). To address this issue the output angle of the LED should be as narrow as possible and preferably around +/3 degrees (total half power beam width 6 degrees). Increasing the output angle is likely to result in reduced performance due to uncontrolled scattering of light.

When air is present against the inner wall 63 of the prism facets 71 internal reflection will occur resulting in light from the LED light source 57 turning 90 degrees towards the reflection sensor 65. Where a film of product is present between the air and side wall reflection will occur at the film/air boundary. Although some attenuation and scattering will occur at this film/air interface performance of the system is still sufficient to provide a reliable indication that air bubbles are passing through the system. The spacing between the inner wall 63 and the diverter 55 is critical to ensure that the air bubble places sufficient force against the side wall to ensure that the film of product is optically thin.

FIG. 14 is a detailed view of the optical system. The reflection sensor 65 is chosen to match the wavelength of the LED light source 57. The detection angle should be reasonably wide to allow integration of the signal coming from the prism internal surface 63. The reception angle should however not be so broad as to allow collection of stray light from other parts of the doser 31. An acceptance angle of 16 to 24 degrees (corresponding to: +/−8 to +/−12 degrees half power) is recommended.

For optimum system performance the LED light source 57, reflection and transmission sensors 65, 69 should be aligned on the same horizontal plane. The reflection sensor should be located at 90 degrees to the LED axis (FIG. 12). The exact location of the sensor in the horizontal plane should be optimized.

The transmission sensor 69 collects any light that passes through the sample chamber 49 when fluid product is present. The parameters for the transmission sensor 69 are similar to those of the reflection sensor 65 as regards wavelength and acceptance angle. Again for optimum performance the transmission sensor 69 should be located on the same axis as the LED light source 57.

Simultaneous detection of both a reflection and transmission allows a more detailed assessment of the product to be made. For example relatively transparent products such as a thin liquid espresso will predominantly be detected by the transmission sensor 69. Products such as milk, with high opacity and scattering properties, will also show some signal on the reflection sensor 65. These variations in characteristics (in either the dynamic or static state) may make it possible to discern the product contained in the exchangeable supply pack. This in turn may allow the consumer to place the pack in any position in a multiple pack dispenser, that accepts a plurality of exchangeable supply packs. The dispenser can then ascertain the product type from the optical signals presented.

With no doser 31 present in the dispenser appliance, i.e. in its interface part 73, the transmission sensor 69 will detect the output of the LED light source 57 directly while the reflection sensor 65 will receive no signal at all. This sensor reading can be used by auto calibration software to look at changes in the maximum signal level, where a change may represent possible contamination of the system.

The presence of an empty doser 31 will result in the reflection sensor 65 receiving a maximum signal level and the transmission sensor 69 a minimum signal. Again an auto calibration can be carried out at this point. This condition can also be used to initiate a pump priming sequence.

Where a used pack is placed in the machine both or either of the reflection and transmission sensors 65, 69 will receive a reduced signal level. In this case a pump priming sequence need not be initiated.

Dynamic measurement is another feature of the detection system cooperating with the doser 31. Known fluid product availability sensor systems use a static system of measurement. An example is a float sensor in a fluid tank. In such systems the sensor allows the pump to operate so long as there is sufficient fluid available to keep the float switch closed. The nature of the fluid product used in the exchangeable supply pack related to the invention precludes a simple static detection system. Between dosing cycles (which may be days) a thick film of product can build up on the side walls of the sample chamber 49. This thick build up can obscure the transmission detector 69 resulting in a false indication of product availability.

The dynamic system developed using the prism 59 (i.e. prism facets 71) and flow diverter 55 relies primarily on the detection of air bubbles entrained in the product. These bubbles passing through the sensor system sweep up against the inner wall 63 of the prism facets 71 result in short pulses of light refracting towards the reflection sensor 65. These pulses are readily detected during a pumping cycle.

A dynamic measurement algorithm examines the sensor system during the pump cycle and estimates the percentage of the pump cycle that contains air. An adjustable threshold determines when an unacceptable amount of air is passing through the system. At this point the product is flagged as no longer being available (end of pack).

An additional feature of the doser 31 is a second substantially opaque element 77 for wiggle and PIP sensing (FIG. 17). As the pack is placed into the dispenser a splined drive shaft 79 of the dispenser pump drive must engage with pinion 45 of the pump mechanism of the doser 31 (FIG. 18). A problem can be defined in that a driven member, such as the pinion 45 of the gear pump, has to be pressed into engagement with the splined shaft 79 that will be driving the pinion 45. Both driving shaft 79 and pinion 45 have a moderate amount of friction. When the splines 81 of the splined shaft 79 are not in line with mating formations 83 on the pinion 45 a solution is needed to align both without damaging the splines 81 or mating formations 83 of either part. This engagement is made easier if the drive shaft 79 is oscillating backwards and forwards by around +/−40 degrees, in accordance with arrows 85, 87 indicated in FIG. 18. According to a proposed solution the PIP sensor 75 detects when the pinion 45 is getting close to the drive shaft 79 and when this is the case, the drive shaft 79 is wiggled slightly for a few degrees. This lasts a second after the PIP sensor 75 detects the presence of the pinion 45 by means of the second substantially opaque element, in this FIG. detection tab 77 (FIG. 17). The chosen solution for simplifying the engagement between driving and driven members 79, 45 is effective without human attention. FIG. 17 shows the detection tab 77 for drive shaft approach and ‘wiggle’ initiation. To aid early detection of the doser 31 approaching the splined drive shaft 79 of the appliance, the detection tab 77 is positioned at the bottom of the sample chamber 49. The tab 77 is sized and located to ensure that the light from the LED light source 57 to the transmission sensor 69 is obscured during lowering before the splined drive shaft 79 engages the pinion 45 of the doser 31. The tab 77 is used by the PIP sensor 75 for detecting pack approaching. As the pack is placed into the dispenser appliance the drive splines 81 of the dispenser drive shaft 79 must engage with the pump pinion 45 of the doser 31. This engagement is more readily achieved if the drive shaft 79 is rotated back and forth by a few degrees as the doser 31 engages the relevant splines 81. This oscillating rotation is referred to above as ‘wiggling’.

A further aspect of the LED light source 57 and transmission sensor 69 is that they should be located to allow them to detect the bottom of the doser sample chamber 49 before the splined shaft 79 engages the pump mechanism. This detection initiates the wiggling action. The tab 77 is opaque or treated to be opaque and is added to the bottom of the sample chamber 49 to ensure that the transmission sensor 69 detects the housing at the correct point in the lowering cycle.

The engagement between the splined shaft 79 and the doser housing 39 is shown in FIGS. 18 and 19A and 19B. The shaft 79 meets the doser bottom surface when the doser 31 is a first distance of (in this example) 8.8 mm above its home position. The splines 81 on the shaft 79 only engage with the pinion 45 at a second distance representing the last (in this example) 3.9 mm of a lowering cycle. The wiggling needs to start between the first and the second distance. The engagement sequence is described in more detail below.

FIG. 18 illustrates the spline engagement of the pump pinion 45 of the doser 31. while the subsequent pack-in-place detection is shown in FIGS. 19A and 19B. As a final check on system readiness the further PIP sensor 75 is placed below the transmission sensor 69. This sensor is activated when the doser 31 is in the fully loaded home position. The PIP sensor 75 is located so that sufficient light from the LED light source 57 will be detected when the pack is not in place. When properly located the tab 77 on the bottom of the sample chamber 49 will obscure the PIP sensor 75 thus providing an indication that the pack is fully loaded and can be operated (see also FIG. 17).

As noted above the transmission sensor 69 and LED light source 57 should be on the same axis. To allow sufficient light to reach the PIP sensor 75, and to ensure that it is activated in the correct position, it may be necessary to move the transmission sensor 69 slightly off axis. In this case great care should be taken to ensure that performance of the product-availability-detection (PAD) system is not compromised. Optical ray tracing followed by testing is recommended to ensure that the system retains the desired PAD performance.

The lowering sequence of the package with its doser 31 that is used to trigger the wiggling action and to indicate that the pack is in place is shown in FIGS. 17-19B. At a third distance of (in this example) 10 mm above the home position light to the transmission sensor 69 is already being blocked by the tab 77 on sample chamber 49. As noted earlier, the shaft 79 is yet to meet with the housing 39 at this point.

In FIGS. 19A and 19B the doser 31 is shown lowering into position at the third distance of 10 mm (FIG. 19A) and at a fourth distance of (in this example) 5 mm (FIG. 19B). By about 5 mm the transmission sensor 69 is fully obscured, but still well ahead of the second distance of 3.8 mm of the drive shaft's engagement with the gear pinion 45. The PIP sensor 75 is now also starting to become obscured at this point. At a fifth distance of (in this example) 2.5 mm the PIP sensor 75 has become fully obscured. The loading handle (not shown but conventional) can conveniently have a spring loaded ‘over-centre’ operation and so will assist to drive the doser 31 into its fully lowered home position.

While in the examples described herein the various detectors have been represented as sensors, it is within the understanding of the skilled person that such detectors could be assemblies inclusive of lenses, light guides, optical and/or electronic filters etc. As will also be clear to the skilled person, automated detection is unrelated to the specific gear pump for dosing fluid and other forms of dosing may be combined with the detection system of the invention.

Accordingly means have been described that are provided for the support of the automated process of supplying beverages. More particularly, the detection of the presence and the contents of exchangeable supply packs (9) in beverage dispensing machines is thereby automated. A pack-in-place detection is provided by emitting light and measuring the presence of the emitted light on a one light detector (7, 75), the system determines the absence or the correct/incorrect placement of the supply pack. A product availability detection is provided by detecting the intensity of light coming through a transparent element in the supply pack by a another light detector (5; 65, 69), the system identifies the degree of product presence in the supply pack.

It is believed that the operation and construction of the present invention will be apparent from the foregoing description and drawings appended thereto. It will be clear to the skilled person that the invention is not limited to any embodiment herein described and that modifications are possible which should be considered within the scope of the appended claims. Also kinematic inversions are considered inherently disclosed and to be within the scope of the invention. In the claims, any reference signs shall not be construed as limiting the claim. The term ‘comprising’ and ‘including’ when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Thus the expression ‘comprising’ as used herein does not exclude the presence of other elements or steps in addition to those listed in any claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. Features that are not specifically or explicitly described or claimed may be additionally included in the structure of the invention within its scope. Expressions such as: “means for . . . ” should be read as: “component configured for . . . ” or “member constructed to . . . ” and should be construed to include equivalents for the structures disclosed. The use of expressions like: “critical”, “preferred”, “especially preferred” etc. is not intended to limit the invention. Additions, deletions, and modifications within the purview of the skilled person may generally be made without departing from the spirit and scope of the invention, as is determined by the claims. 

What is claimed is:
 1. An exchangeable supply pack for a fluid product to be supplied in operation with a beverage dispensing machine having a machine interface with a radiation emitting transmitter and at least one radiation detector, the exchangeable supply pack comprising: a doser; and a pack interface associated with the doser, adapted to be operatively connectable to the machine interface of the relevant beverage dispensing machine; and wherein the pack interface is receivable between the radiation emitting transmitter and the at least one radiation detector of the complementary machine interface, and wherein the pack interface comprising: a substantially transparent element which is adapted in use to interfere with the transmitter; and a substantially opaque element which is adapted in use to interfere with the transmitter.
 2. The exchangeable supply pack of claim 1, wherein the doser has a housing that includes the substantially transparent element, which is adapted to be filled with the fluid product to be supplied.
 3. The exchangeable supply pack of claim 1, wherein the substantially transparent element includes an optical element.
 4. The exchangeable supply pack of claim 3, wherein the optical element is a prism.
 5. The exchangeable supply pack of claim 4, wherein the prism includes a plurality of prism facets.
 6. The exchangeable supply pack of claim 1, wherein the substantially transparent element is a sample chamber, and wherein a flow diverter is arranged within the sample chamber, and wherein the flow diverter is of a transparent material, so as in use not to block incident light emitted from the radiation emitting transmitter and the complementary machine interface of the relevant beverage dispensing machine.
 7. The exchangeable supply pack of claim 6, wherein the substantially opaque element is an opaque tab extending from a bottom of the sample chamber, positioned and located to ensure in use that during placing of the exchangeable supply pack, radiation of the transmitter is first obscured by the opaque tab, before the transparent sample chamber becomes aligned with a common axis defined between the radiation emitting transmitter and at the least one radiation detector associated with the complementary machine interface of the relevant beverage dispensing machine.
 8. The exchangeable supply pack of claim 7, wherein the doser includes a pump having a driven pump pinion, adapted in use to be engaged by a drive shaft of the complementary machine interface, for receiving a driving force from the relevant beverage dispensing machine, and wherein the opaque tab in use by its detection is arranged to initiate back and forth rotating movement of the drive shaft, to assist in engagement of the pump pinion with the drive shaft of the relevant beverage dispensing machine.
 9. The exchangeable supply pack of claim 1, wherein the doser includes a pump having a driven pump pinion, adapted in use to be engaged by a drive shaft of the complementary machine interface, for receiving a driving force from the relevant beverage dispensing machine.
 10. The exchangeable supply pack of claim 1, wherein the pack is at least partially filled with the fluid product to be supplied to a relevant beverage dispensing machine with which it can form an operable system.
 11. The exchangeable supply pack of claim 1, wherein the substantially transparent element is a sample chamber, and wherein the substantially opaque element is an opaque tab extending from a bottom of the sample chamber.
 12. The exchangeable supply pack of claim 11, wherein the sample chamber is adapted to be filled with the fluid product to be supplied.
 13. The exchangeable supply pack of claim 11, wherein the sample chamber includes an optical element.
 14. The exchangeable supply pack of claim 13, wherein the optical element is a prism.
 15. The exchangeable supply pack of claim 14, wherein the prism includes a plurality of triangular facets forming a stepped serrated external wall surface opposite of a common angled internal wall surface.
 16. The exchangeable supply pack of claim 15, wherein a flow diverter is arranged within the sample chamber for guiding the fluid product in contact with the internal wall surface.
 17. The exchangeable supply pack of claim 1, wherein the doser includes a pump, and wherein a flow diverter is arranged within the sample chamber in a flow path of the pump.
 18. The exchangeable supply pack of claim 17, wherein the flow diverter is of a transparent material.
 19. The exchangeable supply pack of claim 1, wherein the doser is a connected part of the supply pack by means of a spout.
 20. The exchangeable supply pack of claim 1, wherein the doser has a housing comprising a bottom part and a top part.
 21. The exchangeable supply pack of claim 20, wherein the doser further includes a pump housing accommodated within the doser housing.
 22. The exchangeable supply pack of claim 21, wherein the pump housing is part of a gear pump and defines inlet and outlet orifices for the pump.
 23. The exchangeable supply pack of claim 22, wherein a flow diverter is arranged as an extension of the pump housing in a flow path of the pump upstream of the inlet orifice. 